Electronic rectifier for exception protection of discharging lamp and discharging lamp

Abstract

The resonance unit of ballast includes: resonant capacitor (RC), in which first end is connected to an end of first filament of discharge lamp, and second end is connected to an end of second filament of discharge lamp; resonant inductor (RI), in which an end is connected to the first end of RC, and second end of RC and the other end of RI are connected to inversion unit to constitute closed loop. The ballast also includes filament warming up unit and abnormal protection unit (APU). APU includes warming and protecting branches connected to first and second filaments respectively to form closed loop. Each branch includes: drive part in use for generating drive signal in branches based on voltage at two ends of (RI); control part in use for controlling on / off of switching element in the inversion unit based on the drive signal; overflow protection element in use for shutting off the branch, in which current is larger than the specific value.

Description

technical field [0001] The invention relates to a circuit device for controlling a discharge lamp, in particular to an electronic ballast for abnormal protection of the discharge lamp, and also to a discharge lamp using the electronic ballast. Background technique [0002] Electronic ballast discharge lamps have widely replaced ordinary inductive ballast discharge lamps because of their high luminous efficiency, no flicker, high efficiency and energy saving. [0003] A discharge lamp circuit using an electronic ballast usually includes a power supply unit 1, a starting unit 2, an inverter unit 3 and a resonant load unit 4, such as figure 1 , figure 2 shown. In normal operation, after the electronic ballast is energized, the inverter unit 3 together with the inductance coil L, the filaments S1 and S2, and the capacitor C form a series resonant circuit. Use the high voltage generated at both ends of the starting capacitor during resonance to start the discharge lamp as a l...

AI Technical Summary

Problems solved by technology

However, sometimes even if the lamp tube is abnormal, the abnormal voltage or current generated by it is not very high, which may cause this kind of circuit to not play an effective protective role.

And adding this kind of protection circuit will still increase the cost to a certain extent

[0007] Due to the above reasons, in consideration of cost reduction, electronic ballasts for compact discharge lamps or electronic rectifiers for some low-cost straight tube fluorescent lamps generally do not add protection devices for abnormal conditions

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